title: Sacralization of epidural block with repeated doses of 0.25% bupivacaine during labor.
abstract: A descriptive analysis of the progression of epidural block with repeated doses of 0.25% bupivacaine was performed, assessing pain relief (visual analog scoring), dermatomal spread of sensory and motor block, and the associated management and outcome of labor. The influence of epinephrine 1:200,000 on these observations was also assessed by the random assignment of study patients into two groups, one receiving 10 ml of 0.25% bupivacaine plain (n = 28) and another group receiving 10 ml of 0.25% bupivacaine with commercially added epinephrine 1:200,000 (n = 27). Only primigravid patients were studied. Data comparisons were considered significant at p less than 0.05. With repeated doses of 0.25% bupivacaine, administered within fixed dosing intervals of 60-90 minutes, there was an increasing spread of sensory block toward sacral dermatomes while the upper level of sensory block did not change. Sacral sensory analgesia was present in only 3.5% of patients after the first dose of bupivacaine but was evident in 63.2% of patients following the fourth epidural injection. A similar increase in the number of patients with significant motor weakness was also seen as the number of top-up doses increased. A comparison of patients receiving plain solutions and epinephrine containing bupivacaine showed similar demographic profiles between the groups. Both groups received a similar dose of bupivacaine and experienced comparable management and outcome of labor. Epinephrine in a 1:200,000 concentration did not influence the changing characteristics of the epidural block over time. The duration of labor was not significantly different between groups (10.3 +/- 5.2 hours for the plain group and 11.0 +/- 4.7 hours for the epinephrine group).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anaesthesia, Faculty of Medicine, University of Ottawa, Ontario, Canada.
authors.forename: R W
authors.initials: RW
authors.lastname: Yarnell
authors.forename: D A
authors.initials: DA
authors.lastname: Ewing
authors.forename: E
authors.initials: E
authors.lastname: Tierney
authors.forename: M H
authors.initials: MH
authors.lastname: Smith
mesh_terms: D000328:Adult; D015360:Analgesia, Epidural; D016362:Analgesia, Obstetrical; D002045:Bupivacaine / Q000008:administration & dosage*; D004837:Epinephrine / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007743:Labor, Obstetric; D008160:Lumbosacral Plexus / Q000187:drug effects*; D011247:Pregnancy
chemical_list: D002045:Bupivacaine; D004837:Epinephrine